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The Michael Heidelberger Papers

Title:
Letter from Michael Heidelberger to Charles D. Hurd, Northwestern University pdf (120,729 Bytes) transcript of pdf
Letter from Michael Heidelberger to Charles D. Hurd, Northwestern University
Description:
Heidelberger had helped to synthesize cyclooctatetrene, the next higher analog of benzene (consisting of a ring with eight carbon atoms and four double bonds) during a year of postdoctoral study (1911-12) in the laboratory of the 1915 Nobel Laureate, Richard Willstatter, at the Federal Polytechnic Institute in Zurich, Switzerland. His research with Willstatter on cyclooctatetrene was controversial, and was questioned as late as the 1940s by Hugh S. Taylor and Charles D. Hurd. Heidelberger, however, strongly defended his results, as documented in this letter, pointing out that while Taylor and Hurd showed that cyclooctatetrene resinifies and degrades at high temperatures, he had worked in cold temperatures continuously for 24 hours to synthesize a colorless liquid that was both stable and reactive. Heidelberger and Willstatter's results stood, and as a consequence of their work cyclooctatetrene became a widely used intermediate in organic chemistry.
Number of Image Pages:
2 (120,729 Bytes)
Date:
1939-11-08 (November 8, 1939)
Creator:
Heidelberger, Michael
Recipient:
Hurd, Charles D.
Northwestern University
Rights:
This item is in the public domain. It may be used without permission.
Subject:
Medical Subject Headings (MeSH):
Chemistry, Organic
Exhibit Category:
The Making of an Immunologist: Heidelberger's Years at the Rockefeller Institute, 1912-1927
Relation:
Metadata Record Letter from Michael Heidelberger to Hugh S. Taylor, Princeton University (September 9, 1939) pdf (30,132 Bytes) transcript of pdf
/ps/access/DHBBMC.pdf
Metadata Record Letter from Hugh S. Taylor, Princeton University to Michael Heidelberger (November 4, 1939) pdf (106,320 Bytes) transcript of pdf
/ps/access/DHBBMD.pdf
Metadata Record Letter from Michael Heidelberger to Hugh S. Taylor, Princeton University (November 7, 1939) pdf (53,023 Bytes) transcript of pdf
/ps/access/DHBBMF.pdf
Metadata Record Letter from Charles D. Hurd, Northwestern University to Michael Heidelberger (November 29, 1939) pdf (182,231 Bytes) transcript of pdf
/ps/access/DHBBMH.pdf
Metadata Record Letter from Richard Willstatter to Michael Heidelberger (March 27, 1940) pdf (63,699 Bytes)
/ps/access/DHBBMJ.pdf
Box Number: 1
Folder Number: 1
Unique Identifier:
DHBBMG
Document Type:
Letters (correspondence)
Language:
English
Format:
application/pdf
image/tif
Physical Condition:
Good
Folder: MS C 245 (first finding aid)
Transcript:
November 8, 1939
Dear Professor Hurd:
I have just read your very interesting paper in the August J. Am. Chem. Soc. On cyclooctatetrene, and inspired by it and other recently expressed doubts I have taken out my old reprint and tried to think back to the original work.
Taken in the abstract, I do not see how anyone could disagree with you as to the many possible directions that could be taken by the reactions used by Willstatter and his coworkers in arriving at cyclooctatetrene. There are, however, certain analogies and observations, also the experimental condtions used, which limit the possibilities.
First, there is the older work of Willstatter on tropilidene, Ann., 1901, 317, 204, in which the cojugated cycloheptatriene system seemed to be preferentially formed. Then there is the narrow boiling range, 0.5 degrees, of cyclooctriene dibromide, indicating the preferentially formation of a single isomer, which would most reasonable be by 1,6 addition. Third, all reactions were carried out at as low termperatures as possible, and in the final Geryk-vacuum demethylation a more stable product was obtained than at higher termpeartures.
I think, therefore, that is hardly fair to compare this procedure with the outcome of "pyrolyses" at over 200 degrees, where rearrangements might easily occur.
Also, I do not see how you can say that "the fact that none of the conjugated hydrocarbon came from IX . . ." casts doubt on the structure of cyclooctatetrene. I should consider it good negative evidence in favor of Willstatter's formulation if even drastic pyrolysis failed to produce a conjugated system which would be expected to form directly on structural grounds. As for the result with X, the diquaternary compound leading to tetraene was not a 1,2 isomer, and this might easily influence the result. Could it not be repeated with the 1, 4 isomer? And might not the percentage of butadiene even from X have been much larger if the decomposition had been run more comparably according to our directions for the cycloocta-compound.
I am very glad that these questions are being re-examined, and only interesting results can come to light, whatever the final result. But I do feel that the original work, too, was carried out on a basis carefully reasoned according to the knowledge of the time, and that doubt arising from reactions occuring at temperatures 100 degrees higher, or even 300 degrees higher, as has been done in certain catalysis experiments, should be examined in the same spirit of skepticism.
Looking forward to your comments, and hoping you are planning additional experiments,
Sincerely,
Michael Heidelberger
Metadata Last Modified Date:
2008-08-14
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